The natural history of bone marrow lesions in community-based adults with no clinical knee osteoarthritis

Objective: Although bone marrow lesions (BML) have been implicated in the pathogenesis of osteoarthritis, their natural history in a healthy population is unknown. This study in a healthy, pain-free population aimed to examine the natural history of BML; factors associated with incidence and progression of BML over 2 years and whether incident BML are associated with the development of pain. Methods: 271 subjects with no clinical knee osteoarthritis, being pain free at baseline, underwent magnetic resonance imaging of their dominant knee at baseline and 2 years later. The presence of BML was assessed. Results: In knees initially free of BML, incident BML developed in 14% of people over the study period. Increased body mass index (BMI; odds ratio (OR) 1.15, 95% CI 1.06 to 1.2, p = 0.001) was associated with incident BML. Those who developed a BML were more likely to develop knee pain compared with those in whom no BML developed (OR 4.2, 95% CI 1.2 to 15.1, p = 0.03). Among those in whom BML were present at baseline, 46% completely resolved. There was no association between age, gender and BMI and persistence of BML over 2 years. Conclusion: In this healthy population, the rate of incident BML is lower than previously described in a population with osteoarthritis. Incident BML are associated with increased BMI and the development of pain. Approximately half the BML present at baseline resolved. These data suggest that in pain-free people with no clinical knee osteoarthritis, BML are reversible and may provide a target for interventions aimed at the prevention of knee osteoarthritis.